is there a way to tighten pins in tube sockets?


Two of the output tube sockets of my VAC amp don't grip the tube pins tight. The tubes are Winged C and I have several sets and all exhibit the same looseness. Before I send it back to VAC, is there a way to tighten the pins?

The problem I experience from this is a right channel hum and unstable tube bias.
rhljazz
Post removed 
Mission accomplished. I used a jewelers screwdriver. Once the amp was out of the rack and on the dining room table it was easy to see the pin receptors, two curved and one flat in each hole. The amount of adjustment was slight to achieve a solid fit.